Many U.S. children spend a significant amount of time in center-based care prior to entering preschool. Previous theory and research would suggest center-based care settings offer important opportunities for gender socialization as children here are surrounded by multiple sources of gender-typing information (e.g. peers, adults, toys and activities). The present longitudinal study examined whether center-based care enrollment status influences level and timing of children's gender-typed behaviors (same-gender friendships, play and appearance), and knowledge (self-categorization and stereotyping) between the ages of 2–5. Participants were children and their mothers of low-income, urban backgrounds (N = 232; African American, Mexican American, and Dominican American). Overall, children enrolled in center-based care at ages 2 and 3 showed higher gender-typing patterns than children enrolled later or not at all. Associations were strongest for same-gender-friendships and gender-typed play, domains that might affect children's subsequent engagement in and learning of certain tasks, skillsets, and activities. (author abstract)